Question

1. Find the 15th term in the Arithmetic Sequence An = 3n-7

2. Find the 10th term in the Arithmetic Sequence -2, -5, -8, -11

Please help!

Answer 1

1. You are given the explicit formula of

An = 3n - 7

So to find the 15th term, you plug it in:
A(15) = 3(15)-7
A(15) = 45 - 7
A(15) = 38 <-- this is how you determine the term.

2. You are given an arithmetic sequence, so you should make a formula based off of it.
If you find the difference between each term, it's -3 because
-2 - 3 = -5
-5 - 3 = -8
-8 - 3 = -11

So the -3 would be the SLOPE

Now how do we find the constant?
We know that
-2 is the first term so
-2 = -3(1) + x <-- plugged 1 in because (-2) is the FIRST TERM

where x is the constant we're looking for so
-2 = -3 + x
1 = x

So our constant is 1.

Now we have our arithmetic explicit formula:
An = -3(n) + 1

Using what we've done for problem one, can you figure out the 10th term using this formula we've made?

Answer 2

Ok one second, kinda slow at math...

btw thank you so much! fan and medal :)

Answer 3

is -29 the answer to question 22?

Answer 4

There are 4 questions I need help with. Can you help me with them please? (Medal)

Answer 5

Yeah, I got -29 as well. Sorry I g2g though. I can't help with anymore problems. Too tired :\

Answer 6

Ok :) But thank you so much!

Answer 7

Going to close this question and ask another with questions 3 and 4.